Electronic imaging devices such as digital cameras are used in a wide range of applications and are steadily becoming less expensive and simpler to use. Electronic images may be stored indefinitely without the image degradation suffered by film-based images. Electronic imaging devices generate images that can be viewed immediately and used in a variety of ways such as printing, posting to a web page on the World Wide Web, transmitting to others by electronic mail (email) or other means, etc. They can also rapidly capture large numbers of images which can be previewed and stored or deleted as desired. As the capacity of removable solid-state memories has increased and price has gone down, typical electronic imaging devices can now capture and internally store hundreds of electronic images.
Electronic imaging devices, such as digital cameras, typically convert light to electrical signals using a two dimensional photodetector. The photodetector contains a two dimensional array of thousands or even millions of light-sensitive cells, each capturing one picture element (or pixel) of an image. As an image is focused onto the photodetector, an electrical charge builds up in the photodetector cells. The magnitude of the electrical charge corresponds to the intensity of the image light—brighter light generates a larger electrical charge. Thus, the image light focused on the photodetector generates a pattern of varying electrical charges across the photodetector. The magnitude of the electrical charges across the photodetector are analyzed and stored in the electronic imaging device as an electronic representation of the image. In a digital imaging device such as a digital camera, the magnitude of the electrical charges is converted into a number in an analog to digital (A/D) converter.
Electronic imaging devices are rapidly becoming more popular and are gaining widespread acceptance due to the utility of electronic images and to the increasing quality of the electronic imaging devices. However, one of the most expensive components in an electronic imaging device continues to be the photodetector. Doubling the resolution of the photodetector in an electronic imaging device can more than double the cost of the electronic imaging device.